component rename: add special case for root component (i.e. the form or control being designed)

src/AddIns/BackendBindings/CSharpBinding/Project/Src/FormsDesigner/CSharpDesignerLoader.cs

@@ -216,8 +216,13 @@ namespace CSharpBinding.FormsDesigner
 				
 				// Find designer class
 				ITypeDefinition designerClass = FormsDesignerSecondaryDisplayBinding.GetDesignableClass(primaryParseInfo.UnresolvedFile, compilation, out primaryPart);
-				ISymbol controlSymbol = designerClass.GetFields(f => f.Name == oldName, GetMemberOptions.IgnoreInheritedMembers)
-					.SingleOrDefault();
+				
+				ISymbol controlSymbol;
+				if (context.IsRootComponent(component))
+					controlSymbol = designerClass;
+				else
+					controlSymbol = designerClass.GetFields(f => f.Name == oldName, GetMemberOptions.IgnoreInheritedMembers)
+						.SingleOrDefault();
 				if (controlSymbol != null) {
 					FindReferenceService.RenameSymbol(controlSymbol, newName, new DummyProgressMonitor())
 						.ObserveOnUIThread()

src/AddIns/BackendBindings/CSharpBinding/Project/Src/FormsDesigner/CSharpFormsDesignerLoaderContext.cs

@@ -57,6 +57,11 @@ namespace CSharpBinding.FormsDesigner
 		{
 			viewContent.ShowSourceCode(lineNumber);
 		}
+		
+		public bool IsRootComponent(object component)
+		{
+			return viewContent.Host != null && viewContent.Host.RootComponent == component;
+		}
 	}
 }
 

src/AddIns/BackendBindings/CSharpBinding/Project/Src/FormsDesigner/ICSharpDesignerLoaderContext.cs

@@ -16,6 +16,7 @@ namespace CSharpBinding.FormsDesigner
 		CSharpFullParseInformation GetPrimaryFileParseInformation();
 		ICompilation GetCompilation();
 		IDocument GetDocument(FileName fileName);
+		bool IsRootComponent(object component);
 		void ShowSourceCode(int lineNumber = 0);
 	}
 }